Browsing by Author "Guan, HL"

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A novel method for short leaky-wave antennas to suppress the reflected wave
(2003-01-20)
Wang, CJ
;
Guan, HL
;
Jou, CF
;
傳播研究所
;
Institute of Communication Studies
A method to suppress the back lobe of a short leaky-wave antenna (LWA) by using an aperture-fed patch antenna on the backside is demonstrated in this paper. The aperture-fed patch antenna is connected to the open end of the LWA. This design offers another radiation path of the reflected wave and creates another radiation pattern on the back plane of the substrate. Experimental results show that the suppression of the reflected wave can be 10 dB at 10.0 GHz with an LWA length of 6 cm (2 wavelengths). Compared to the conventional design, this novel structure can radiate as efficiently as LWA at a length a wavelengths. The two radiation patterns on different planes have great potential in many applications and can provide more flexibility to traditional designs. (C) 2003 Wiley Periodicals, Inc.
Studies of suppression of the reflected wave and beam-scanning features of the antenna arrays
(2005-07-01)
Chen, IY
;
Wang, CJ
;
Guan, HL
;
Jou, CF
;
電信工程研究所
This paper describes a two-directional linear scanned design by integrating a short leaky-wave antenna (LWA) with aperture-coupled patch antenna arrays. This architecture proposes a technique not only having the advantage of suppressing the back-lobe due to the reflected wave in the short LWA but also produch two separate linearly scanned beams, each of them radiating in a different region of space (in both the front side and backside of the LWA). In this design, most of the reflected wave of the short LWA is coupled to the patch antenna arrays on the backside of the substrate. The phase of this coupled signal to each antenna element is adjusted by tuning the individual phase shifter in order to control electronically the patch antenna main beam in the cross plane (x < 0). Meanwhile, on the front side, the main beam of the short LWA can be simultaneously scanned in the elevation plane (x > 0) by changing the operating frequency. Hence, the two linear beam-scanning radiation patterns of individual direction can be created independently, including a narrow beam in the elevation plane (xy plane at x > 0) at the front side and a broadside beam in the cross plane (xz plane at x < 0) on the backside. The measured results show that the reflected wave of the short LWA in the proposed design is suppressed 8 dB as compared with a traditional short LWA without the aperture-coupled antenna arrays at 10.5 GHz. As a result, this novel architecture provides more flexibility both in the upward elevation plane (H plane) and the downward cross plane (backside-E plane) for possible beam-scanning applications in microwave communications and remote identification.
Suppression of reflected wave of leaky-wave antenna by utilizing an aperture-fed patch antenna
(2001)
Guan, HL
;
Wang, CJ
;
Jou, CF
;
傳播研究所
;
Institute of Communication Studies
Here, we present a method to suppress the back lobe of a short leaky-wave antenna by using an aperture-fed patch antenna on the backside. The aperture-fed patch antenna is connected to the open end of the leaky-wave antenna (LWA). Such design offers another radiation path of the reflected wave and creates another radiation pattern on the back plane of the substrate. Experimental result shows that the suppression of the reflected wave can be 10 dB at 10.0 GHz with a LWA length of 6cm (2 wavelengths). The suppression bandwidth is 200MHz owing to the narrow bandwidth of aperture and patch. Compared to conventional design, this novel structure can radiate as efficiently as LWA with length of 4 wavelengths. The two radiation patterns on different planes have great potential in many applications and provide more flexibility to traditional designs.
Two-dimensional scanning leaky-wav antenna by utilizing the phased array
(2002-08-01)
Wang, CJ
;
Guan, HL
;
Jou, CF
;
電信工程研究所
;
Institute of Communications Engineering
An aperture-fed patch antenna array is connected to the open end of a short leaky-wave antenna (LWA) to demonstrate the two-dimensional beam-scanning capability in this paper. This design not only offers another radiation path of the reflected wave, but also creates another scanning radiation pattern on the back plane of the substrate. The reflected wave of the LWA is equally separated by a power divider, modulated by each varactor-tuned phase shifter, and injected into two radiating aperture-coupled antennas. The operated frequencies are tuned to control the LWA main position in the elevation plane; meanwhile, by tuning the phase difference between two phase shifters, the main beam of the aperture-coupled antenna array can be scanned in the backside E plane. Experimental result shows that the suppression of the reflected wave can be 7 dB at 10.0 GHz with a short LWA length of 6 cm (two wavelengths). The H-plane and backside E-plane scanning radiation patterns have great potential in many applications and provide more flexibility to traditional designs.